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1,342 results on '"Jiang Yuyang"'

166. Blast furnace ironmaking process with super high TiO2 in the slag: Density and surface tension of the slag.

Author

Pang, Zhengde, Jiang, Yuyang, Ling, Jiawei, Lü, Xuewei, and Yan, Zhiming

Abstract

Aiming at the process of smelting ultra-high (>80%) or even full vanadium titanomagnetite in blast furnace, we are conducting a series of works on physics character of high TiO2 bearing blast furnace slag (BFS) for slag optimization. This work discussed the density and surface tension of high TiO2 bearing BFS using the Archimedean principle and the maximum bubble pressure method, respectively. The influence of TiO2 content and the MgO/CaO mass ratio on the density and surface tension of CaO-SiO2-TiO2-MgO-Al2O3 slags were investigated. Results indicated that the density of slags decreased with the TiO2 content increasing from 20wt% to 30wt%, but it increased slightly with the MgO/CaO mass ratio increasing from 0.32 to 0.73. In view of silicate network structure, the density and the degree of polymerization (DOP) of network structure have a consistent trend. The addition of TiO2 reduced (Q3)2/(Q2) ratio (Q2 and Q3 represent structural unit with bridge oxygen number of 2 and 3, respectively) and then decreased DOP, which led to the decrease of slag density. The surface tension of CaO-SiO2-TiO2-MgO-Al2O3 slags decreased dramatically with the TiO2 content increasing from 20wt% to 30wt%. Conversely, it increased with the MgO/CaO mass ratio increasing from 0.32 to 0.73. Furthermore, the iso-surface tension lines were obtained under 1723 K using the Tanaka developed model in view of Butler formula. It may be useful for slag optimization of ultra-high proportion (>80%) or even full vanadium titanomagnetite under BF smelting. [ABSTRACT FROM AUTHOR]

Published
2022
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170. An Image Segmentation Method by Multi-scale Local Thresholding Based on Class Uncertainty Theory

Author

Xinyu Wu, Jiang Yuyang, Likai Zhou, Jiafeng Zhu, Huaikun Xiang, and Guoyuan Liang

Subjects
Computer science, business.industry, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Pattern recognition, Uncertainty theory, Image processing, 02 engineering and technology, Image segmentation, 021001 nanoscience & nanotechnology, 01 natural sciences, Thresholding, Fuzzy logic, Otsu's method, symbols.namesake, Computer Science::Computer Vision and Pattern Recognition, 0103 physical sciences, symbols, Segmentation, Pyramid (image processing), Artificial intelligence, 010306 general physics, 0210 nano-technology, business
Abstract

Image segmentation is one of the most important core technologies in the field of image processing and computer vision, which has lots of applications specifically in medical image analysis. Due to medical imaging mechanism, medical images usually suffer from heavy noises, uneven intensity distribution and fuzzy boundaries between biological tissues. That makes classical segmentation methods based on global or local thresholding difficult to get accurate results. This paper proposes an image segmentation method by multi-scale local thresholding based on class uncertainty theory. Firstly, the original image is divided into a set of sub-regions with different scales by using a multi-layer pyramid structure. Secondly, the energy function with inequality constraints is constructed based on class uncertainty and region uniformity. Then by an iterative process, the optimal local threshold for each sub-region are calculated by an optimization algorithm for each layer until the final optimal threshold mask is determined for image segmentation. Experimental results verify that the proposed method can effectively eliminate the interferences caused by image noises, intensity unevenness and fuzzy boundaries, and preserve details of object structure while segmenting the object from the background. Segmentation results demonstrate the superior performance of the proposed method by comparison with supervised range-constrained thresholding methods (RCOtsu), classical global/local Otsu method, and the minimization of homogeneity- and uncertainty-based energy method (MHUE).

Published
2019

178. Total Syntheses of Daphnezomine L-type and Secodaphniphylline-type DaphniphyllumAlkaloids via Late-Stage C–N Bond Activation

Author

Hu, Jingping, Guo, Lian-Dong, Chen, Wenqing, Jiang, Yuyang, Pu, Fan, Ning, Chengqing, and Xu, Jing

Abstract

Here, we report the first total syntheses of daphnezomine L-type alkaloids daphnezomine L methyl ester and calyciphylline K via late-stage C–N bond activation. The first synthesis of secodaphniphylline-type alkaloid caldaphnidine D was also achieved via a similar strategy. Other key transformations employed in our synthesis were a facile vicinal diol olefination and an efficient radical cyclization cascade. Biological studies indicated two synthetic compounds possess promising neuroprotective activity.

Published
2022
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199. Synthesis of α‐Amino Tertiary Alkylperoxides by Lewis Acid‐Catalyzed Peroxidation of 1,3,5‐Triazines.

Author

Liu, Lijuan, Shi, Zhichao, Zhang, Xun, Zhan, Feng, Lin, Jin‐Shun, and Jiang, Yuyang

Subjects
PEROXIDATION, SYNTHETIC products, ANTIMALARIALS, NATURAL products, LEWIS acids, TRIAZINES
Abstract

α‐Substituted peroxides have been found in natural products and are widely used as anti‐malarial agents. Zn(OTf)2‐catalyzed peroxidation of 1,3,5‐triazines has been developed, accessing diversely substituted α‐amino tertiary alkylperoxides with high efficiency. Mechanistic investigations and useful synthetic application of the products have also been presented. [ABSTRACT FROM AUTHOR]

Published
2021
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